Well-preserved fossils of benthic marine invertebrates, including decapod crustaceans, are often found in the Pliocene sediments that constitute the substratum of the hills of Tuscany. Year after year, new or “exotic” taxa are thus found and documented, mostly thanks to isolated fnds. In systematic paleontology, the ideal condition for instituting a new species is by working on many specimens: in this way, a newly instituted taxon may be described on the basis of the holotype and other specimens that would depict its intraspecifc variability. That said, given the fragmentary nature of the fossil record, this happens rarely, and several extinct species are instituted and described based on very few specimens. It is the case for the ghost crab species Ocypode italica Garassino et al., 2010, which was known so far by the holotype and one paratype. Such a limited fossil record is typical of the Ocypode spp. and might refect the habitat preferences of this group of ghost crab species, inhabiting high-energy sandy shores at tropical and subtropical latitudes worldwide. Among the Neogene record of decapod crustaceans from Italy, the two known specimens of O. italica are nonetheless of prime importance, as they represent the northernmost fnds of the genus Ocypode in the Mediterranean Basin, as well as the geologically oldest species of Ocypode in Europe. Recently, thanks to the cooperation between some local amateurs and academically educated paleontologists, a well-preserved new specimen of O. italica has been collected from the same upper Pliocene deposits of Tuscany (central Italy) from which the type specimens originate. Our new fnd represents the third known specimen of this species, and as such, it allows to better characterize the anatomy of the carapace, chelipeds and walking legs of this rarely reported extinct form of ghost crabs. In particular, anatomical resemblances between O. italica and the extant form Ocypode cursor (Linnaeus, 1758) may suggest similar ecological and trophic habits for these two Mediterranean species. In the present work we fgure and describe this new specimen, and briefy discuss its signifcance in the broader picture of the Pliocene fossil record of Tuscany.
A new specimen of the extinct ghost crab species Ocypode italica (Decapoda: Brachyura: Ocypodidae) from the Pliocene of Tuscany (Italy)
Collareta A.Ultimo
2018-01-01
Abstract
Well-preserved fossils of benthic marine invertebrates, including decapod crustaceans, are often found in the Pliocene sediments that constitute the substratum of the hills of Tuscany. Year after year, new or “exotic” taxa are thus found and documented, mostly thanks to isolated fnds. In systematic paleontology, the ideal condition for instituting a new species is by working on many specimens: in this way, a newly instituted taxon may be described on the basis of the holotype and other specimens that would depict its intraspecifc variability. That said, given the fragmentary nature of the fossil record, this happens rarely, and several extinct species are instituted and described based on very few specimens. It is the case for the ghost crab species Ocypode italica Garassino et al., 2010, which was known so far by the holotype and one paratype. Such a limited fossil record is typical of the Ocypode spp. and might refect the habitat preferences of this group of ghost crab species, inhabiting high-energy sandy shores at tropical and subtropical latitudes worldwide. Among the Neogene record of decapod crustaceans from Italy, the two known specimens of O. italica are nonetheless of prime importance, as they represent the northernmost fnds of the genus Ocypode in the Mediterranean Basin, as well as the geologically oldest species of Ocypode in Europe. Recently, thanks to the cooperation between some local amateurs and academically educated paleontologists, a well-preserved new specimen of O. italica has been collected from the same upper Pliocene deposits of Tuscany (central Italy) from which the type specimens originate. Our new fnd represents the third known specimen of this species, and as such, it allows to better characterize the anatomy of the carapace, chelipeds and walking legs of this rarely reported extinct form of ghost crabs. In particular, anatomical resemblances between O. italica and the extant form Ocypode cursor (Linnaeus, 1758) may suggest similar ecological and trophic habits for these two Mediterranean species. In the present work we fgure and describe this new specimen, and briefy discuss its signifcance in the broader picture of the Pliocene fossil record of Tuscany.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
